My computer has been frequently freezing while on the internet. I have followed your usual advice about installing the latest Windows updates, checking for viruses and spyware, and defragmenting the drive, but the problem still continues. The freezes started after I installed some pre-paid dial-up internet software on the computer so I could use the machine while on holiday. The computer is running Ad-Aware, Spybot, and PC-Cillin Internet Security 2007 which have not detected any problems. The computer is a Pentium D 3.0 GHz with 1 GB RAM running Windows XP.

The most likely cause of this issue is the software you installed with the pre-paid dial-up internet package. Often such pre-paid internet access packages come with a lot of bundled software, which have relatively limited usage and just clogs the computer. So, if you have not done so already you should uninstall any software relating to the pre-paid dial-up internet account. Once this has been completed, restart the computer and check whether the problem persists.

Should the problem continue, another possible cause is that a program or process is running in the background or doing something over the internet causing the computer to freeze. This seems a likely scenario, since you mentioned that the problem only occurs when using the internet. To test this theory, we will shut down all non-essential background processes and then attempt internet access to check whether the problem persists. Restart the computer, so that all the background processes re-load, and once Windows has finished loading close any visible non-essential applications which are running. Be aware, in this instance you can keep any security software running, as this is unlikely to be the cause of the issue and we also need to remain protected when connected to the internet. Once you have closed all non-essential visible applications, we must next close the non-visible processes running in the background. Press CTRL-ALT-DEL to open the Task Manager and click the ‘Processes’ tab. Click the ‘User Name’ column heading to sort the processes by user name (if this heading is not visible, go to the ‘View’ menu > ‘Select Columns’ and tick ‘User Name’ then click OK). Once the processes are sorted by user name, close the non-essential processes running under your user name only. When completing this procedure, do not attempt to close processes running under any other user names, as these may be system essential processes, and closing such processes could result in some negative consequences for the computer operation. Also, don’t close any security software. If you are unsure about the purpose of a particular process, you can search for the process at www.processlibrary.com which may give you a clearer description of the process. If you are still unsure, err on the side of caution and do not close the process. Once you have finished closing the non-essential processes, access the internet to check whether the problem continues. If not, one of those applications or processes was causing the issue. Now, it will just be a process of elimination to determine which process is causing the problem (i.e. close a process, check if the problem persists). This is a long-winded process, but unfortunately is the only real option to determine the particular process causing the problem.